Coherent control of enhanced second-harmonic generation in a plasmonic nanocircuit using a transition metal dichalcogenide monolayer.

Nonlinear nanophotonic circuits, renowned for their compact form and integration capabilities, hold potential for advancing high-capacity optical signal processing. However, limited practicality arises from low nonlinear conversion efficiency. Transition metal dichalcogenides (TMDs) could present a promising avenue to address this challenge, given their superior optical nonlinear characteristics and compatibility with diverse device platforms. Nevertheless, this potential remains largely unexplored, with current endeavors predominantly focusing on the demonstration of TMDs' coherent nonlinear signals via free-space excitation and collection. In this work, we perform direct integration of TMDs onto a plasmonic nanocircuitry. By controlling the polarization angle of the input laser, we show selective routing of second-harmonic generation (SHG) signals from a MoSe2 monolayer within the plasmonic circuit. Routing extinction ratios of 14.86 dB are achieved, demonstrating good coherence preservation in this hybrid nanocircuit. Additionally, our characterization indicates that the integration of TMDs leads to a 13.8-fold SHG enhancement, compared with the pristine nonlinear plasmonic nanocircuitry. These distinct features-efficient SHG generation, coupling, and controllable routing-suggest that our hybrid TMD-plasmonic nanocircuitry could find immediate applications including on-chip optical frequency conversion, selective routing, switching, logic operations, as well as quantum operations.

Ultrafast and Broad-Band Graphene Heterojunction Photodetectors with High Gain.

Graphene possesses an exotic band structure that spans a wide range of important technological wavelength regimes for photodetection, all within a single material. Conventional methods aimed at enhancing detection efficiency often suffer from an extended response time when the light is switched off. The task of achieving ultrafast broad-band photodetection with a high gain remains challenging. Here, we propose a devised architecture that combines graphene with a photosensitizer composed of an alternating strip superstructure of WS2-WSe2. Upon illumination, n+-WS2 and p+-WSe2 strips create alternating electron- and hole-conduction channels in graphene, effectively overcoming the tradeoff between the responsivity and switch time. This configuration allows for achieving a responsivity of 1.7 × 107 mA/W, with an extrinsic response time of 3-4 µs. The inclusion of the superstructure booster enables photodetection across a wide range from the near-ultraviolet to mid-infrared regime and offers a distinctive photogating route for high responsivity and fast temporal response in the pursuit of broad-band detection.

Van der Waals Heterostructure Mid-Infrared Emitters with Electrically Controllable Polarization States and Spectral Characteristics.

Modern infrared (IR) microscopy, communication, and sensing systems demand control of the spectral characteristics and polarization states of light. Typically, these systems require the cascading of multiple filters, polarization optics, and rotating components to manipulate light, inevitably increasing their sizes and complexities. Here, we report two-terminal mid-infrared (mid-IR) emitters, in which tuning the polarity of the applied bias can switch their emission peak wavelengths and linear polarization states along two orthogonal orientations. Our devices are composed of two back-to-back p-n junctions formed by stacking anisotropic light-emitting materials, black phosphorus and black arsenic-phosphorus with MoS2. By controlling the crystallographic orientations and engineering the band profile of heterostructures, the emissions of two junctions exhibit distinct spectral ranges and polarization directions; more importantly, these two electroluminescence (EL) units can be independently activated, depending on the polarity of the applied bias. Furthermore, we show that when operating our emitter under the polarity-switched pulse mode, the time-averaged EL exhibits the characteristics of broad spectral coverage, encompassing the entire first mid-IR atmospheric window (λ: 3-5 µm), and electrically tunable spectral shapes.

The Adaptive Evolution in the Fall Armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) Revealed by the Diversity of Larval Gut Bacteria.

Insect gut microbes have important roles in host feeding, digestion, immunity, development, and coevolution with pests. The fall armyworm, Spodoptera frugiperda (Smith, 1797), is a major migratory agricultural pest worldwide. The effects of host plant on the pest's gut bacteria remain to be investigated to better understand their coevolution. In this study, differences in the gut bacterial communities were examined for the fifth and sixth instar larvae of S. frugiperda fed on leaves of different host plants (corn, sorghum, highland barley, and citrus). The 16S rDNA full-length amplification and sequencing method was used to determine the abundance and diversity of gut bacteria in larval intestines. The highest richness and diversity of gut bacteria were in corn-fed fifth instar larvae, whereas in sixth instar larvae, the richness and diversity were higher when larvae were fed by other crops. Firmicutes and Proteobacteria were dominant phyla in gut bacterial communities of fifth and sixth instar larvae. According to the LDA Effect Size (LEfSe) analysis, the host plants had important effects on the structure of gut bacterial communities in S. frugiperda. In the PICRUSt2 analysis, most predicted functional categories were associated with metabolism. Thus, the host plant species attacked by S. frugiperda larvae can affect their gut bacterial communities, and such changes are likely important in the adaptive evolution of S. frugiperda to host plants.

Van der Waals Heterostructure Photodetectors with Bias-Selectable Infrared Photoresponses.

A bias-selectable photodetector, which can sense the wavelength of interest by tuning the polarity of applied bias, is useful for target discrimination and identification applications. So far, those detectors are generally based on the back-to-back photodiode configuration via exploiting epitaxial semiconductors as optoelectronic materials, which inevitably lead to high fabrication costs and complex device architectures. Here, we demonstrate that our band-engineered van der Waals heterostructures can be applied as bias-selectable photodetectors. Our first prototypical device is mainly composed of black phosphorus (BP) and MoTe2 light absorbers sandwiching a thin MoS2 hole blocking layer. By varying the bias polarity, its spectral photoresponse can be switched between near-infrared and short-wave infrared bands, and our optoelectronic characterizations indicate that the detector can exhibit high external quantum efficiency (EQE) and fast operation speed. With this framework, we further demonstrate the detector with bias-selectable photoresponses within the mid-wave infrared band using BP/MoS2/arsenic-doped BP heterostructures and show that our developed detectors can be integrated into a single-pixel imaging system to capture dual-band infrared imaging.

Electric control of valley polarization in monolayer WSe2 using a van der Waals magnet.

Electrical manipulation of the valley degree of freedom in transition metal dichalcogenides is central to developing valleytronics. Towards this end, ferromagnetic contacts, such as Ga(Mn)As and permalloy, have been exploited to inject spin-polarized carriers into transition metal dichalcogenides to realize valley-dependent polarization. However, these materials require either a high external magnetic field or complicated epitaxial growth steps, limiting their practical applications. Here we report van der Waals heterostructures based on a monolayer WSe2 and an Fe3GeTe2/hexagonal boron nitride ferromagnetic tunnelling contact that under a bias voltage can effectively inject spin-polarized holes into WSe2, leading to a population imbalance between ±K valleys, as confirmed by density functional theory calculations and helicity-dependent electroluminescence measurements. Under an external magnetic field, we observe that the helicity of electroluminescence flips its sign and exhibits a hysteresis loop in agreement with the magnetic hysteresis loop obtained from reflective magnetic circular dichroism characterizations on Fe3GeTe2. Our results could address key challenges of valleytronics and prove promising for van der Waals magnets for magneto-optoelectronics applications.

Waveguide-Integrated van der Waals Heterostructure Mid-Infrared Photodetector with High Performance.

Extending the operation wavelength of silicon photonics to the mid-infrared (mid-IR) band will significantly benefit critical application areas, including health care, astronomy, and chemical sensing. However, a major hurdle for mid-IR silicon photonics has been the lack of high-speed, high-responsivity, and low noise-equivalent power (NEP) photodetectors. Here, we demonstrate a van der Waals (vdW) heterostructure mid-IR photodetector integrated on a silicon-on-insulator (SOI) waveguide. The detector is composed of vertically stacked black phosphorus (BP)/molybdenum ditelluride (MoTe2). We measured high responsivity (up to 0.85 A/W) over a 3-4 µm spectral range, indicating that waveguide-confined light could strongly interact with vdW heterostructures on top. In addition, the waveguide-integrated detector could be modulated at high speed (>10 MHz) and its switching performance shows excellent stability. These results, together with the noise analysis, indicate that the NEP of the detector is as low as 8.2 pW/Hz1/2. This reported critical missing piece in the silicon photonic toolbox will enable the wide-spread adoption of mid-IR integrated photonic circuits.

Black Phosphorus Mid-Infrared Light-Emitting Diodes Integrated with Silicon Photonic Waveguides.

Light-emitting diodes (LEDs) based on III-V/II-VI materials have delivered a compelling performance in the mid-infrared (mid-IR) region, which enabled wide-ranging applications in sensing, including environmental monitoring, defense, and medical diagnostics. Continued efforts are underway to realize on-chip sensors via heterogeneous integration of mid-IR emitters on a silicon photonic chip, but the uptake of such an approach is limited by the high costs and interfacial strains, associated with the processes of heterogeneous integrations. Here, the black phosphorus (BP)-based van der Waals (vdW) heterostructures are exploited as room-temperature LEDs. The demonstrated devices emit linearly polarized light, and the spectra cover the technologically important mid-IR atmospheric window. Additionally, the BP LEDs exhibit fast modulation speed and exceptional operation stability. The measured peak extrinsic quantum efficiency is comparable to the III-V/II-VI mid-IR LEDs. By leveraging the integrability of vdW heterostructures, we further demonstrate a silicon photonic waveguide-integrated BP LED.

Ultra-Broadband, High Speed, and High-Quantum-Efficiency Photodetectors Based on Black Phosphorus.

Black phosphorus (BP), a narrow band gap semiconductor without out-of-plane dangling bonds, has shown promise for broadband and integrable photodetector applications. Simultaneously exhibiting high speed and high-efficiency operation, however, remains a critical challenge for current BP-based photodetectors. Here, we demonstrate a photodetector based on the BP-based van der Waals heterostructures. The developed photodetector enables broadband responses in the visible to mid-infrared range with external quantum efficiency ranging from 20 to 52% at room temperature. These results together with noise measurements indicate that the photodetector can detect light in the picowatt range. Furthermore, the demonstrated BP detector has ultrafast rise (1.8 ns) and fall (1.68 ns) times, and its photoresponse exhibits reproducible switching behavior even under consecutive and rapid light intensity modulations (2100 cycles, 200 MHz), as indicated by the eye-diagram measurement. By leveraging these features, we show our BP heterostructures can be configured as a point-like detector in a scanning confocal microscopy, useful for mid-infrared imaging applications.

[Relationship between the residual Jingmai in Tianhui medical slips and Jingmai in Lingshu].

Except the complete literature of Maishu: Xiajing, Tianhui medical slips unearthed in Chengdu also include a part of literature document on meridian, which was seriously damaged. Both of them were found in the same box together with Yimashu. The title of the document chapter was not found in the residual medical slips. By investigated the textual content, it was discovered that such medical slips were different from the Mawangdui silk books, i.e. Yinyang Shiyimai Jiujing and Zubi Shiyimai Jiujing, Maishu of Zhangjiashan bamboo slips of Han Dynasty, as well as Maishu: Xiajing in Tianhui medical slips. But, the sentences in description are similar to the sentences of Jingmai in Lingshu (Miraculous Pivot), therefore, this residual slips was named as Jingmai (Meridian) by the collator. In the paper, by the comparison of this residual slip chapter with the unearthed literature document on meridian as well as Jingmai in Lingshu, the origin and evolution of meridian theory of traditional Chinese medicine in the Qin and Han dynasties were explained. By taking it as an example, the construction process of classical theory of traditional Chinese medicine was explored.

Association of klotho gene polymorphism and the regulation of calcium-phosphate metabolism disorders in patients with end-stage renal disease.

BACKGROUND: Klotho G-395-A gene polymorphism is associated with several diseases; however, its association with calcium-phosphate metabolism disorders in end-stage renal disease (ESRD) is unknown. METHODS: A total of 137 patients with ESRD and 80 healthy adults (control) were enrolled in the study. Patients with ESRD were divided into three subgroups: haemodialysis (A1, n = 52), peritoneal dialysis (A2, n = 30), and non-dialysis (A3, n = 55). The klotho G-395-A genotype was detected by TaqMan PCR assay, and ELISA was used to detect the soluble klotho protein (sKL) and fibroblast growth factor (FGF23). Intact parathyroid hormone (iPTH) and other related clinical biochemical parameters were also analyzed for all subjects. RESULTS: (i) Three genotypes (GG, GA and AA) of KL G-395A were detected, and a significant difference between the ESRD and control groups was observed, (ii) sKL was inversely associated with FGF23 in each subgroup and phosphate and positively associated with calcium in A1 and A3. FGF23 was positively associated with phosphate and inversely associated with calcium in each subgroup, (iii) a statistical difference in levels of sKL and FGF23 was observed between GG and AA, as well as between GA and AA. The expression of sKL was lowest and the level of FGF23 was highest in AA and (iv). GA + AA genotypes and FGF23 were risk factors and sKL might be protective factor of calcium-phosphate metabolism disorders. CONCLUSION: Soluble klotho protein and FGF23 were associated with the regulation of calcium and phosphate metabolism, and the A allele of the G-395A klotho gene polymorphism could be a risk factor on calcium-phosphate metabolism disorders in patients with ESRD.

[Interpreting the Methods for Blending Decoctions to Treat 60 Ailments in Tianhui bamboo slip medical manuscripts].

Among the medical texts excavated in 2012-2013 from the Han Dynasty tomb at Tianhui township in Sichuan province, we found a collection on the treatment of 60 ailments. Under each ailment, we found one or more formulas, for a total of 106 formulas. The authors of this paper compiled and analyzed these texts based on the original bamboo slips and named this collection with the title Methods for Blending Decoctions to Treat 60 Ailments because the content was focused on blending and making medicinal formulas, and also due to the historical connections with the texts the Record of the Court Scribe, "Biography of Bian Que and Cang Gong". For these reasons, this title was determined, where "blending decoctions" mean "blending and harmonizing medicines optimally in preparation for decocting". The Tianhui texts preserve ancient forms of medicinal formulas, including some once believed to be lost, such as "grain decoctions", "fermented alcohol decoctions", and "fiery decoctions". Based on the historical evidence, we can now ascertain that this text is the "Blending Formulas and Making Decoctions" mentioned in the Record of the Court Scribe written by Cang Gong. Moreover, the medical texts, Canon Formulas in Decoction Form (from the book of Han Dynasty) and the Imperial Pharmacy Formulas to Benefit the People in Song Dynasty are both of this genre of medical literature. The Tianhui text is therefore a representative of this genre of literature in the Western and eastern Han, acting as a key link between early medical formula books and later formula books.

Significance of M2 macrophage in tubulointerstitial disease secondary to primary Sjogren's disease.

OBJECTIVE: M2 Macrophages could improve tubulointerstitial disease in animal models. HIF-1αpromotes macrophage polarization and is involved in tubular injury. The study aims to observe the clinicopathologic significance of M2 macrophage and HIF-1α in tubulointerstitial injury secondary to primary Sjogren's disease. METHODS: Renal tissue samples from patients with tubulointerstitial disease secondary to primary Sjogren's disease (SS, n = 10), chronic tubulointerstitial nephritis secondary to drug (CIN, n = 8) were included in this study. The expression of CD163, CD68 and HIF-1α were examined by immunohistochemistry or immunofluorescence. RESULTS: (1) Renal involvement was the first manifestation in seven of ten (7/10) patients with pSS, including proteinuria, renal dysfunction, renal tubular acidosis and multiple renal stone; and two patient had intractable hypokalemia. (2) There were numerous CD163- positive cells and CD68- positive cells infiltration in tubulointerstitial injury of pSS, especially in patients with hypokalemia. CD163 positive cells and HIF-1αwere mainly expressed in acute tubulointerstitial injury of pSS, which positively correlated to N-acetyl-ß-D-glucosaminidase and ß2-microglobulin. (3) Compared with CIN, patients with pSS had higher serum globulin level, erythrocyte sedimentation rate (ESR) and lower urinary osmotic pressure. (4) During follow-up of one year, six patients with pSS and acute tubular injury acquired improved renal function on therapy of steroid and total glucosides of peony. The remaining four patients with pSS had stable renal function. CONCLUSION: M2 macrophages are involved in acute tubular injury in patients with primary Sjogren's disease. Early intervention can improve renal function of tubulointerstitial injury secondary to primary Sjogren's disease.

Ultrathin van der Waals Metalenses.

Ultrathin and flat optical lenses are essential for modern optical imaging, spectroscopy, and energy harvesting. Dielectric metasurfaces comprising nanoscale quasi-periodic resonator arrays are promising for such applications, as they can tailor the phase, amplitude, and polarization of light at subwavelength resolution, enabling multifunctional optical elements. To achieve 2π phase coverage, however, most dielectric metalenses need a thickness comparable to the wavelength, requiring the fabrication of high-aspect-ratio scattering elements. We report ultrathin dielectric metalenses made of van der Waals (vdW) materials, leveraging their high refractive indices and the incomplete phase design approach to achieve device thicknesses down to ∼λ/10, operating at infrared and visible wavelengths. These materials have generated strong interest in recent years due to their advantageous optoelectronic properties. Using vdW metalenses, we demonstrate near-diffraction-limited focusing and imaging and exploit their layered nature to transfer the fabricated metalenses onto flexible substrates to show strain-induced tunable focusing. Our work enables further downscaling of optical elements and opportunities for the integration of metasurface optics in ultraminiature optoelectronic systems.

Significance of M2 macrophages in glomerulonephritis with crescents.

OBJECTIVES: CD163 and CD206, markers of M2 macrophages, possesses anti-inflammatory properties. This study aims to investigate the clinicopathologic significance of M2 macrophages in patients of glomerulonephritis with crescents. METHODS: Renal tissue samples from patients of glomerulonephritis with more than 30% cell or cell-fibrous crescents, including lupus nephritis (LN, n=14), anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV, n=14), IgA nephropathy(IgAN) (n=11), Henoch Schonlein purpura glomerulonephritis(HSPGN)(n=8)were included in this study. The expression of CD163, CD206 and CD68 in renal tissues was detected by immunohistochemistry or immunofluorescence. RESULTS: (1) CD163 was mainly expressed in cell or cell-fibrous crescents, proliferative glomerular lesions and acute tubulointerstitial injury. There were numerous CD163-positive cells in LN and AAV in comparison with IgAN and HSPGN. (2) CD206-positive cells were mainly observed in acute tubulointerstitial injury, and proliferative glomerular lesions, especially in LN. Patients with LN had numerous CD206-positive cells in glomerular than other groups. The number of CD163-positive cells and CD206-positive cells in acute tubulointerstitial lesions of LN and AAV were more than IgAN and HSPGN. (3) Both the number of CD163-positive cells and CD206-positive cells in acute tubulointerstitial lesions negatively correlated to estimated glomerular filtration rate. (4) In LN, activity index (AI) positively correlated with the number of CD206-positive cells and CD163-positive cells. Dual staining showed that CD163-positive cells and CD206-positive cells also expressed CD68. CONCLUSIONS: CD163-positive cells and CD206-positive cells, subpopulation of macrophages, which were involved in the pathogenesis of active crescentic glomerulonephritis, especially in LN and AAV.

Nanocavity Integrated van der Waals Heterostructure Light-Emitting Tunneling Diode.

Developing a nanoscale, integrable, and electrically pumped single mode light source is an essential step toward on-chip optical information technologies and sensors. Here, we demonstrate nanocavity enhanced electroluminescence in van der Waals heterostructures (vdWhs) at room temperature. The vertically assembled light-emitting device uses graphene/boron nitride as top and bottom tunneling contacts and monolayer WSe2 as an active light emitter. By integrating a photonic crystal cavity on top of the vdWh, we observe the electroluminescence is locally enhanced (>4 times) by the nanocavity. The emission at the cavity resonance is single mode and highly linearly polarized (84%) along the cavity mode. By applying voltage pulses, we demonstrate direct modulation of this single mode electroluminescence at a speed of ∼1 MHz, which is faster than most of the planar optoelectronics based on transition metal chalcogenides (TMDCs). Our work shows that cavity integrated vdWhs present a promising nanoscale optoelectronic platform.

Plasmonic Lattice Lenses for Multiwavelength Achromatic Focusing.

This paper describes an evolutionary approach to design flat multiwavelength achromatic lenses based on subwavelength plasmonic nanoparticles. Our lattice evolution algorithm achieved desired optical responses by tuning the arrangement of the phase units on a discrete square lattice. Lattice lenses consisting of a single type of nanoparticle could operate at any wavelength in the visible to near-infrared regime (540-1000 nm) by tailoring the localized surface plasmon resonance. When the unit cells were expanded to anisotropic particle shapes, the planar optics could selectively focus light depending on the polarization of incident light. Finally, the algorithm realized efficient multiobjective optimization and produced achromatic lattice lenses at up to three wavelengths (λ = 600 nm, λ = 785 nm, and λ = 980 nm) using multiple different nanoparticle shapes.

Realization of mid-infrared graphene hyperbolic metamaterials.

While metal is the most common conducting constituent element in the fabrication of metamaterials, graphene provides another useful building block, that is, a truly two-dimensional conducting sheet whose conductivity can be controlled by doping. Here we report the experimental realization of a multilayer structure of alternating graphene and Al2O3 layers, a structure similar to the metal-dielectric multilayers commonly used in creating visible wavelength hyperbolic metamaterials. Chemical vapour deposited graphene rather than exfoliated or epitaxial graphene is used, because layer transfer methods are easily applied in fabrication. We employ a method of doping to increase the layer conductivity, and our analysis shows that the doped chemical vapour deposited graphene has good optical properties in the mid-infrared range. We therefore design the metamaterial for mid-infrared operation; our characterization with an infrared ellipsometer demonstrates that the metamaterial experiences an optical topological transition from elliptic to hyperbolic dispersion at a wavelength of 4.5 µm.

Graphene Ambipolar Nanoelectronics for High Noise Rejection Amplification.

In a modern wireless communication system, signal amplification is critical for overcoming losses during multiple data transformations/processes and long-distance transmission. Common mode and differential mode are two fundamental amplification mechanisms, and they utilize totally different circuit configurations. In this paper, we report a new type of dual-gate graphene ambipolar device with capability of operating under both common and differential modes to realize signal amplification. The signal goes through two stages of modulation where the phase of signal can be individually modulated to be either in-phase or out-of-phase at two stages by exploiting the ambipolarity of graphene. As a result, both common and differential mode amplifications can be achieved within one single device, which is not possible in the conventional circuit configuration. In addition, a common-mode rejection ratio as high as 80 dB can be achieved, making it possible for low noise circuit application. These results open up new directions of graphene-based ambipolar electronics that greatly simplify the RF circuit complexity and the design of multifunction device operation.

[Spatial variability of soil organic carbon sequestration rate and its influencing factors in Fengqiu County, Henan, China.] / æ²³å—å°ä¸˜åŽ¿åŸŸå†œç”°åœŸå£¤å›ºç¢³é€ŸçŽ‡ç©ºé—´å˜å¼‚ç‰¹å¾åŠå ¶å½±å“å› ç´ .

Carbon sequestration rate in cropland soil is an important index to evaluate the effect and potential capacity of soil carbon sequestration. Accurate estimation of soil organic carbon sequestration rate is very important for studying cropland soil fertility and environmental effect. In this research, a typical fluvor-aquic soil area, Fengqiu County of Henan Province, located in Yellow Ri-ver basin of Huang-Huai-Hai Plain of China, was chosen as the study area. A total of 70 soil samples were collected according to combined unit grid method of soil utilization with soil type in 2011. The soil organic carbon content, soil mechanical composition, soil bulk density and pH were mea-sured, respectively. The spatial variability of the soil organic carbon sequestration rate of Fengqiu County in recent 30 years was also investigated by using geostatistics method and geography information system (GIS) technique, based on the comparative analysis of soil organic carbon content from samples surveyed in 2011 and the results surveyed by the 2nd state soil survey of China in 1981. In addition, the influencing factors of the soil carbon sequestration rate were quantitatively analyzed by statistical methods, such as significance testing, regression analysis and variance analysis. The results revealed that the soil organic carbon sequestration rate of recent 30 years was about 0.33 t C·hm-2·a-1 with a coefficient variance of 74%, which belonged to a medium variation. The spatial variability characteristics of soil organic carbon sequestration rate was of sheet distribution, which was higher in the west and lower in the east, and decreased from the central region to the south and north. The primary influencing factors of soil organic carbon sequestration rate were structural factors, such as soil type, mechanical composition, soil bulk density and pH, which could explain 59.5% of the spatial variability in the study area. The secondary factors were random factors, such as straw application and fertilizing amount, which could explain 40.5% of the spatial variability.